<!-- 拖拽排序表格 https://github.com/WakuwakuP/element-ui-el-table-draggable -->
<template>
  <div ref="wrapper">
    <div :key="tableKey">
      <slot></slot>
    </div>
  </div>
</template>

<script>
import sortable from "sortablejs";

export default {
  name: "ElTableDraggable",
  props: {
    handle: {
      type: String,
      default: ""
    },
    animate: {
      type: Number,
      default: 100
    }
  },
  data() {
    return {
      tableKey: 0
    };
  },
  methods: {
    makeTableSortAble() {
      const table = this.$children[0].$el.querySelector(
          ".el-table__body-wrapper tbody"
      );
      sortable.create(table, {
        handle: this.handle,
        animation: this.animate,
        onEnd: ({newIndex, oldIndex}) => {
          this.keepWrapperHeight(true);
          this.tableKey = Math.random();
          const arr = this.$children[0].data;
          const targetRow = arr.splice(oldIndex, 1)[0];
          arr.splice(newIndex, 0, targetRow);
          this.$emit("drop", {targetObject: targetRow, list: arr});
        }
      });
    },
    keepWrapperHeight(keep) {
      // eslint-disable-next-line prefer-destructuring
      const wrapper = this.$refs.wrapper;
      if (keep) {
        wrapper.style.minHeight = `${wrapper.clientHeight}px`;
      } else {
        wrapper.style.minHeight = "auto";
      }
    }
  },
  mounted() {
    this.makeTableSortAble();
  },
  watch: {
    tableKey() {
      this.$nextTick(() => {
        this.makeTableSortAble();
        this.keepWrapperHeight(false);
      });
    }
  }
};
</script>